Researcher Warns Space Weather Hole Blocks Manned Mars Mission

Dr Foullon pointsto particular concerns about the radiation dangers of Solar ProtonEvents (SPEs) particularly those that follow Coronal Mass Ejections(CMEs - massive clouds of material ejected from the Sun that producedangerous, high energy, charged particles). One of the largest suchevents ever recorded arrived at Earth in August 1972 right betweenNASA's Apollo 16 and 17 manned missions. Simulations of the radiationlevels an astronaut inside a spacecraft would have experienced duringthis event found that the astronaut would have absorbed lethal doses ofradiation within just 10 hours. It was simply good luck that thishappened between the missions.

Since then a number of satellitemissions have been able to give advanced warnings of SPE & CMEevents and revealed much about their workings but that monitoring andunderstanding today still only relates to a tiny part of our SolarSystem - literally just the line between Earth and the Sun. A mannedMars mission will travel far beyond the boundaries of our currentunderstanding and observation. While we have an increasingunderstanding the impact of SPEs in and around the Earth we have noidea if the same holds true for the geometry of space around the restof the changing area between Earth, Mars and the Sun. Nor do we know ifthe current models of what happens in these events between the Sun andEarth can be accurately extrapolated to understand what happens overthe greater distances between the Sun and Mars. Dr Foullon believesthose knowledge gaps are currently simply too large and too dangerousto allow a manned Mars mission.

However the research outlinesopportunities to learn from upcoming space weather related satellitelaunches and makes 3 recommendations that could plug the holes in ourunderstanding sufficiently to allow a manned Mars mission to proceed inrelative safety. There are a number of upcoming space weather relatedsatellite launches that could be key to that but the 2005 Stereomission and the 2008-9 Solar Sentinels programme are of particularvalue. The recommendations are:

Firstly Mars planners should payparticular attention to the Stereo, and the part of the Solar Sentinelsprogramme which will place a satellite facing the opposite side of theSun to Earth. They should aim to replicate those missions just before amanned mars mission launch with a package of 3 satellites integratedinto a single mission designed specifically to provide space weatherwarnings for a Mars mission. Two of the satellites in that Mars packageto be positioned this side of the Sun like Stereo and one on the otherside of the sun like one of the planned solar sentinels. Another optionoutlined in Dr Foullon's paper is that one could instead plan a packageof satellites with one in a Stereo style position with two satellitesin the L1 and L2 Sun-Mars Lagrange points.

Secondly there must beconsiderable research to develop a lightweight mechanism to beinstalled on the manned mission to give some early warning of dangerousspace weather. While we have some clues as to how that might be donethe technology is not yet there to deliver a workable solution.

Lastlyparticular attention should be paid to the data from the variousupcoming space weather missions to develop a more robust model of howdangerous space weather propagates over larger distances than the"simple" path that we most understand between the Sun and Earth.

The original paper can be found at:
http://www.agu.org/journals/sw/swa/free/newarticle/?id=2004SW000134